The clinical syndrome of aspirin-induced asthma will be studied as a possible general model for non-allergic asthma. Using two clinical research protocols, patients with varying degrees of sensitivity to aspirin and aspirin-like drugs will be idenified. The asthmatic disorder induced by these drugs will be studied with respect to its pulmonary physiology and the possible role of prostaglandins in its pathogenesis. Incramental oral challenge with the aspirin-like drugs will be monitored by spirometry and by body plethysmography. Plasma prostaglandin levels before and after challenge will be ascertained. In addition, the peripheral leukocytes of patients with aspirin-induced asthma, as well as appropriate controls, will be studied in vitro in a histamine release assay system in order to further define the role of prostaglandin pathways in the etiology of bronchial asthma.